Process of producing benzyl chlorid.



JAMES B. CONANT, F CAMBRIDGE, MASSACHUSETTS, ASSIGN'OR TO SEMET-SOLVAY COMPANY, A CORPORATION OF NEW YORK.

PROCESS OF PRODUCING BENZYL CHLORID.

No Drawing.

To all whom it may concern Be it known that I, JAMES B. CoNAN'r, a citizen of the United States, residing at Cambridge, in the county of Middlesex, in

the Commonwealth of Massachusetts, have invented new and useful Improvements in the Process of Producing Benzyl Chlorid, of which the following is a specification.

My invention relates to the process for producing benzyl chlorid by the chlorinat'ion of toluene by means of nascent chlorin produced from bleaching powder and sulfur dioxid, and has for its object the production of benzyl chlorid in a more expeditious and GCOIIOIIllCELl manner.

The production of benzyl chlorid by'the chlorination of toluene by means of gaseous chlorin has been found to give a variety of products such as monochlortoluene, benzylchlorid, chlorbenzychlorid, benzalchlorid, benzotrichlorid, depending on the conditions of reaction and the amount of chlorin. In order to get benzyl chlorid as free from other products as possible, it has been found necessary to pass chlorin gas (preferably dry), intoboiling toluene. The reaction is a slow one and some form of light energy is often used as it accelerates the reaction and tends to prevent the formation of monochlortoluene. The use of chlorin gas in this old process, which is a corrosive substance, and the production of corrosive hydrochloric acid given off in the reaction makes necessary an expensive and bulky apparatus.

Instead of depending upon the agency of chlorin gas for the chlorination of toluene, I obtain this result by means of nascent chlorin produced in the toluene in the following manner: The toluene to be chlorinated is placed in any suitable container which is provided with a stirrer and cooling coil. Bleaching powder of the sort well-known to commerce is then mixed with the toluene in the proportion of one part of bleaching pow- "t5 der to two parts of toluene. It will be readily understood that I refer to the bleaching powder which is a mixture of calcium hypochlorite, calcium chlorid, and free lime obtained by passing chlorin gas over lime.

Specification of Letters Patent.

Application filed October 20.1916.

Patented July 1'7, 1917.

Serial No. 126,781.

This bleaching powder should preferably 5t contain thirty-five per cent. (35%) or more of available chlorin. Sulfur dioxid gas or a mixture of sulful dioxid gas and nitrogen is next introduced into the mixture by bubbling it in through pipes entering the bottom of the container. Instead of sulfur dioxid there may be used any gaseous acid or acid anhydrid. Considerable heat is evolved by the subsequent reaction but the temperature at which the toluene is kept is of no importance for the success of the reaction. A return condenser may be fitted to the apparatus to reduce the, loss of toluene due to v evaporation. When between .1 and .5 of a pound of sulful dioxid per pound of bleach- 6% ing powder has been introduced, the reaction, will be finished. The tolueine and benzyl chlorid are now steam distilled away from the solid residue, the toluene coming over first. The last portion consisting of toluene and benzyl chloridmay be separated by fractionally distilling. The yield of benzyl chlorid is about one pound of benzyl chlorid from every three to six pounds of bleaching powder depending largely upon the quality of the bleaching powder. The unchanged. toluene is recovered and is ready to be used over again while the solid residue consisting largely of calcium sulfate may be readily washed out of the apparatus and thrown away.

My process has the following advantages over the ordinary procedure, viz., the reaction is much faster thus requiring a less bulky apparatus for a given output; it does not necessitate the keeping of toluene at its boiling point; it t: es not require the use of chlorid gas which is a corrosive substance, thus making a much simpler apparatus possible; it produces none or a small amount of monochlortoluene; it produces only a trace of other chlorination products of toluene; no corrosive hydrochloric acid gas is given off in the reaction.

Having thus fully described my invention, 9- what I claim is: 1

1. Process of producing benzyl chlorid from toluene by mixing therewith a solid which, when treated with a suitable gaseous reagent is capable of producing nascent chlorin, treating the mixture of solid and toluene With such a gaseous reagent, and suitably 5 separating the resulting benzyl chlorid from the toluene and solid material.

2. Process of producing benzylchlorid from toluene by mixing therewith bleaching powder, subjecting the mixture to sulfur dioxid gas and distilling away'the toluene 10 and benzyl chlorid substantially in the manner described.

JAMES B. CONANT. 

